If race isn't biological, how do forensics
investigators determine a person's race using just their bones
or a fragment of their DNA?
Like some of the other questions, especially the one on
bone marrow, we have to look at the assumption that is embedded
in the question, which is the idea that forensic investigators
actually are good at telling an individual's race from their
bones or from a fragment of their DNA. I can very clearly
say that this assumption is incorrect.
Initially there were a number of forensic studies in which
they tried to separate individuals into different so-called
races depending on what they were looking at in the bones
- size and shapes of skulls mostly. And they thought they
had it. But when any of these studies has been replicated,
looking at individuals from a different area or a different
time, the results, sadly, are little better than random
I think the reason why this is true is very interesting.
It really smacks at how fluid social definitions of race
are and even how fluid, sometimes, biologies are. Biology
can change, or at least phenotypes can change, from generation
to generation. So if you did an initial study on say, bones
of so-called blacks and whites in Cleveland, and then do
a study of so-called blacks, whites, and Native Americans
in Arizona, you actually find that the blacks in Arizona
look different from the blacks in Cleveland. And the whites,
in fact, look so different that one could even assign them
into a different "race." In the same way, maybe, we could
say Japanese immigrants look different once they come to
the United States versus when they were in Japan.
The DNA question is a little bit different. I think the
answer to that one is that we're not identifying race, we
are identifying individuals. Individual DNA is what's unique.
Let's face it, it's not important to find a race, it's important
to find an individual. That question also very much applies
to medicine. Why would forensics investigators even want
to determine a person's race? Because you're not trying
to find a black or white or Asian. You're trying, most often,
to find a person, so you're looking for unique markers,
not ones that are generalizable to a group. Secondly, it
kind of is a game in which you have to make, first, the
assumption that there is such a thing as race. And then
if you do put individuals into four or five essential types,
the more data you look at - just by matter of pure statistics
- the higher your probabilities are going to be of sorting
into those groups. But just because you do it doesn't mean
that those groups that you set up in the first place have
any sort of biological validity to them.
Let me illustrate Alan's point. There was a story in the
New York Times recently about a mass murderer in Louisiana.
The police were relying on a profile that mass murderers
tend to be white, and they were having trouble locating
a suspect. A geneticist, Mark Shriver at Penn State, got
a DNA sample and said that the ancestry of this person was
more likely black. They then apprehended a black person.
The fact of the matter is, all that genetics allows you
to do is to make a better than random prediction of the
category. In the same way that skull shapes or facial form
will allow you to make a better than random guess as to
which category the person belongs to. To the extent that
there are some key features that tend to be shared by people
identified as the same race, for example, eye form, hair
form, skin color, etc., you can make a better than random
prediction based on measuring some of those characteristics,
either physically or genetically, than if you were just
using psychic abilities.
Ancestry has to do with familial relationships. And there
is this popular idea that if you just extend that outward,
you get some sort of mega-population or mega-family, which
is a race. And, of course, that's simply not true.
The DNA research sounds a lot like the development of the
forensic bone work. Looking at a lot of variables at the
same time and saying that the combination of looking at
lots of variables can properly sort individuals into different
With Mark Shriver's work, he frequently compares blacks
from Washington, D.C. with whites from Penn State University.
And he has found some alleles that do a pretty good job
of sorting those two groups of individuals. However, in
Louisiana the test might not work as well. Interestingly,
if it fails, we're probably less likely to hear about it
because it's a technological failure. But now it's in the
New York Times because, at least at this point, it seems
interesting and it seems to be successful.
But the question is - let's take this another way - will
somebody in Germany now pick up this methodology and assume,
okay, I can use the same bunch of alleles in Germany to
distinguish Africans who have come to Germany directly from
Africa - say Algeria, for example - and I'm going to compare
that to Germans. My guess is that this will happen and lead
to all sorts of problematic outcomes.
The point that needs to be made is that race is very specific.
It's not general. We tend to want to make it general. But
race is a very site specific, socially defined phenomenon.
||Can I add one thing to that also? At one time,
most, if not all of this work was being done in universities
by researchers who had no other interest than the advancement
of knowledge and what other baggage and intellectual prejudice
that they brought to the table. But the fact is that, today,
a lot of this work is being done by companies who have a vested
interest in the profitability and marketing service that people
will buy. And in this particular case, we're talking about
a company called DNAPrint Genomics. And, as Alan said, we're
not going to hear about the failures, we're only going to
hear about the correct hit. And also, as Pilar was talking
about earlier, the same goes with these companies that provide
services for pharmacogenomics as well. It's dangerous territory.